The big increases in education funding since 1999 have not been put to good use, the government’s statisticians said on Tuesday.

The findings by the Office for National Statistics will raise embarrassing questions about Labour’s public service reforms.

In spite of a decade of management initiatives and a doubling of spending on schools, the ONS reported that outcomes such as examination results had not improved as rapidly as spending, and taxpayers had received worse value for money over the past seven years.

Productivity – a measure of value for money – fell by an average of 0.7 per cent a year since 1999, mainly because the government decided to recruit 50,000 school assistants at a time when the number of pupils was falling.

By contrast, the productivity measure increased by 2.1 per cent a year between 1996 and 1999.

The ONS calculated productivity by dividing an estimate for output – which takes account of the number of pupils in school and exam results – by the amount of spending on education.

The figures are a setback for Gordon Brown, who has made education his top priority since becoming prime minister. Opposition parties say the figures show that Labour has wasted the large sums devoted to improving services. Since Labour came to power, the education budget has soared – rising from about £28.2bn in 1997 to £49.4bn in 2006.

As public spending tightens in coming years, productivity will become an increasingly important political issue, setting the stage for election battles over who can be trusted to run the public services.

For some time, ministers have challenged the methodology used by the ONS, arguing that the education statistics omitted the big improvements in quality of life for children.

Len Cook, who was ONS chief at the time, was called in to see Tony Blair and Mr Brown in 2004 to explain why official data showed that the public was not getting good value for money. That raised concerns that politicians were attempting to put pressure on independent statisticians.

The statisticians have included GCSE results as the main measure of quality, despite many educational experts believing that they have been flattered by grade inflation. Without that, the figures would have looked much worse.

“If exams are getting easier, then current measures overstate quality gains,” said the ONS.

New output measures for the health sector were introduced last June. They doubled the reported output growth of the NHS to 20 per cent over the past six years. But productivity measures in October showed that even with higher recorded output, NHS efficiency had declined since 1997 on every measure looked at by statisticians.

Tuesday’s report included information on a range of gauges of educational “output” – from the number of children taking drugs to the rigour of exams. In one striking passage, the ONS said teaching standards had not improved for the past six years, citing information from Ofsted inspection reports.

“There is evidence of increasing standards of teaching in schools from 1996/7 to about 2000, then stability,” the report said.

“It must be remembered that productivity doesn’t take account of improving the life chances of every child,’’ he said. “You could actually increase productivity by increasing the number of children in a class, for example.”

Michael Gove, the shadow children’s secretary, said the figures showed the education system “is falling behind under Gordon Brown”. He added: “We have hard proof from the government’s own watchdog that extra spending isn’t getting the results the nation deserves.”

Productivity fall

Labour came to power promising that its top priorities would be – in the words of Tony Blair in 1996 – “education, education, education”. The Labour government has since raised spending on education by 83 per cent to £49.4bn last year, funding flagship programmes such as city academies.

However, in spite of this increase in funding and focus, statistics released on Tuesday reveal that productivity in publicly funded education has stalled in the past 10 years, rising by only 0.1 per cent a year since 1996.